He has been called out to look for dentures, teeth and prescription glasses that had fallen into the ocean. He also found a four-karat diamond ring that had been a 40th anniversary gift worth $60,000 to $80,000.

But his latest find came accidentally.

Last month, Sheldon was cruising around with his underwater metal detector gear at Kapalua Bay when he came across a 1958 Baldwin High School class ring.

"That is completely amazing," Sheldon said after learning how long ago the ring went missing. "It was 52, 53 years ago."

On land, it would be easy to find something in a spot where it had been lost 100 years ago, he said. But in the ocean, it's far more difficult because of currents and many other variables that change the bottom of nearshore waters all the time.

The ring was found in about 3 feet of water and around 15 to 20 feet from shore. It had the initials A.Y. inscribed on it along with the graduation date.

Sheldon called Baldwin High School officials for help and eventually got the name of the graduate from staffers who looked through old yearbooks.

The ring belonged to 72-year-old Annette Yoda of Wailuku.

"It took me almost a few seconds before I realized that I had lost my ring," Yoda said of her conversation with Sheldon.